On Thu, Jun 18, 2009 at 4:57 AM, Clemens Ladisch<cladisch@xxxxxxxxxxxx> wrote: > Denis A. Altoé Falqueto wrote: >> I've bought a (el cheapo) midi-usb cable so I can play my musical >> keyboard (also el cheapo... but I'm no professional :)). The thing is >> that when I try to use it in my laptop (Gigabyte W566U, ArchLinux 64 >> bits, up to date), it is not reliable. I play the keys and the midi >> events are not delivered correctly. I'm using aseqdump to debug. For >> example, I press 5 keys and see 5 key down events, but when I releas >> them, only 2 o 3 note up events are shown. And if I play too many >> notes, it just stops receiving any events from the device, dmesg show >> a strange message "urb status -75" and reconnects the usb device. > > Is there also a message when single events are lost? > > 75 means EOVERFLOW. linux/Documentation/usb/error-codes.txt says: > | -EOVERFLOW (*) The amount of data returned by the endpoint was > | greater than either the max packet size of the > | endpoint or the remaining buffer size. "Babble". > | > | (*) Error codes like -EPROTO, -EILSEQ and -EOVERFLOW normally indicate > | hardware problems such as bad devices (including firmware) or cables. > >> I tested the same cable on my old desktop (Asus A7N8X-X motherboard, >> nvidia MX440 graphics card, 5 years of intensive e loyal use, >> ArchLinux 32 bits) and it works fine. The difference between the two >> seems to be the usb module that handles the device. [...] >> Does anyone has any suggestions on how can I force ohci_hcd to be >> loaded before uhci_hcd? Or is it realy the problem? > > ohci_hcd works only with an OHCI controller; uhci_hcd works only with > a UHCI controller. Loading the other one will not have any effect. > > If you really want to try a different driver, connect the interface > through a USB 2.0 hub; this will be handled by ehci_hcd. But I guess > this won't make any difference. > > What kernel version are you using on each machine? > > The ICH8M chip of your laptop isn't known for making USB problems. > This might be a problem with a USB port (try another one) or the > laptop's wiring. > > > Best regards, > Clemens > _______________________________________________ > Linux-audio-user mailing list > Linux-audio-user@xxxxxxxxxxxxxxxxxxxx > http://lists.linuxaudio.org/mailman/listinfo/linux-audio-user > Yeah, that's the case, really. Before I read your email, last night I had the confirmation that is a hardware problem with the usb ports of my laptop and the usb plug of the cable. I use a usb keyboard (not musical) in my desktop and it has also two usb ports in one side. I connected the keyboard to my laptop and connected the midi cable in one of the usb ports of the keyboard. The uhci_hcd module was loaded and no notes were lost. Another thing that happens is that only 2 usb ports out of 4 of the laptop work with the midi cable, being that one of them gives miscontacts (I need to force the cable into the port and any sudden movement makes it disconnect). I thank you all for your time. The sense that we don't know what is wrong is very annoying, but now I can at least decide about something. Maybe I should buy some decent midi interface :) -- ------------------------------------------- Denis A. Altoe Falqueto ------------------------------------------- Samuel Goldwyn - "I'm willing to admit that I may not always be right, but I am never wrong." - http://www.brainyquote.com/quotes/authors/s/samuel_goldwyn.html _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/mailman/listinfo/linux-audio-user
